This invention relates to an industrial robot apparatus which is suitable for carrying out various manufacturing processes. More particularly, it relates to an industrial robot apparatus which has a plurality of robots and which can continue to operate when one of the robots malfunctions.
Industrial robot apparatuses have been proposed which employ a plurality of robots mounted for movement along a common pathway. A number of processing machines, such as machine tools, are installed along the pathway. A part to be processed by the processing machines is carried by the robots from one processing machine to the next, and a series of manufacturing steps are sequentially performed on the part.
Generally, each of the robots provides parts to only specific ones of the processing machines along the pathway. Due to the layout of the pathway, the robots can not pass one another. Therefore, if one of the robots should malfunction and become unable to perform its allotted task, the remaining robots can not substitute for the malfunctioning robot, since they can not move along the pathway past the malfunctioning robot to a suitable position. When the processing machines perform sequential operations on parts, the flow of parts from machine to machine becomes impossible when even a single robot malfunctions, and the manufacturing operation must be halted.